Locomotive firebox



April 5, 1938. Q 1 CHRlSTENSQN 2,112,953

LOCOMOTIVE FIREBOX Filed June 1s. 195e Patented Apr. 5, 1938 UNITED STATES PATENT OFFICE 2,112,953 LoooMo-'rlvE FmEBoX Application June 13,

3 Claims.

This invention relates to improvements in locomotive type iireboxes and it consists of the matters hereinafter described and more particularly pointed out in the appended claims.

One of the objects of the present invention is to provide a locomotive type rebox with a novel tube arrangement for increasing the heating surface of the rebox and for accelerating the water circulating action by syphoning water irom points along the side water legs and discharging the same upon the top of the crown sheet to insure a constant flooding of the same.

Another object of the invention is to provide a circulating tube arrangement for a firebox of this kind wherein the use of longer tubes is possible not only to give a greater heating surface area, but also to make them more exible so that they will accommodate, without cracking, the relative movement of certain of the rebox sheets under temperature changes.

A further object of the invention is to provide in a locomotive type of rebox, a circulator tube arrangement providing a better support for the brick of the arch and whereby a lesser number of brick patterns is required and wherein the brick may be so arranged as to produce a tighter arch.

The above mentioned objects of the invention, as well as others, together with the advantages thereof will more fully appear as the specification proceeds.

In the drawing:

Fig. 1 is a longitudinal vertical sectional View through a locomotive iirebox and adjacent boiler parts, embodying the preferred form ofthe invention, the plane of the section being taken on the line of Fig. 2;

Fig. 2 is a transverse vertical sectional view through the same as taken on the line 2 2 of Fig. l; and

' Fig. 3 is a detail horizontal sectional View on a somewhat enlarged scale as taken on the line 3 3 of Fig. 2.

Referring now in detail to that embodiment of the invention, illustrated in the accompanying drawing, 5 5 indicates the side sheets of the firebox, 6 indicates the crown sheet, 'l indicates the front or iiue sheet and 8 indicates the back sheet thereof. It will be understood that the i'irebox is positioned in the rear end of the associated boiler shell, which includes the outer side sheets 9 5?, top sheet l0, back sheet l I and front throat sheet l2. Portions of the back sheets 8 and Il respectively, are formed to provide a fuel door opening I3.

Several of the various sheets mentioned coact 1936, Serial No. 85,063

to form the side water legs lll, back water leg l5 and front throat I6 respectively, all bottomed by a mud ring Il, The above is typical of a conventional locomotive boiler rear end structure and requires no further detailed description eX- cept to say that companion sheets are suitably staybolted.

To increase the effective evaporating surface area of the rlrebox and the steaming and water circulating efhciency of the associated boiler, I provide the following arrangement:

On each side of the longitudinal median line of the rebox are located sets of water evaporating and circulating tubes I8 I8 with the tubes in each set arranged in spaced relation, longitudinally of the firebox. Preferably the tubes in one set are disposed in the transverse planes of those in the other set.

Each tube includes an inlet portion i9, an outlet portion 20 and an intermediate connecting portion 2l of a reverse curve formation on the order of an ogee. The inlet portion I9 has an extremity 22 arranged at a right angle to the plane of the associated side sheet 5. This eX- tremity opens through and is xed in said side sheet and merges into the inlet portion by a short curved portion 23. The inlet portion I9 which as shown herein is relatively straight, eX- tends upwardly and inwardly from thecurved portion 23 at an inclination desired in the assou ciated part of a fire arch which will be referred to later. The crown sheet 6 is arched or curved transversely of the flrebox and the outlet portion 2l) of the tube extends radially with respect thereto and opens through and is fixed therein in any suitable manner.

As herein shown, the intermediate portion 2| of the tube comprises upper and lower reversed curved parts and the lower curved parts of the tubes in both sets are spaced relatively close. together as best appears in Fig. 2.

It is apparent that with the tubes anchored in the crown sheet and side sheets as mentioned, forces are transmitted through said tubes from the crown sheet to the side sheets. Due to the reverse curve or bulging formation of the intermediate portions 2! of the tubes, these portions eX to accommodate such relative movement between the sheets without cracking.

While the spacing between the lower curved parts of the intermediate portions of the tubes is relatively close, it is so gauged as to never permit actual contact between said parts.

The structure admirably coacts to support an arch indicated as a whole as at 24 in Fig. 2.

This arch is made up of transverse rows of brick, each including an outer end brick 25, an inner end brick 26 and intermediate brick 2l'. The bricks are preferably curved transversely to the plane of the row in which they are positioned, as appears in Fig. 1. Each brick has concaved corners 28 to rest upon upper parts of the tubes. The outer end brick abut against the associated side sheet 5 and the inner` end face of the inner end brick of the row is bevelled off to provide a full face contact with the like face of the inner end brick of the opposed row of brick. Each inner end brick is cutaway as at 29 to reduce its width to permit it to pass the curved intermediate parts of the tubes, as best appears in Fig. 3.

In the front end row of bricks, the bricks thereoi rest at one side upon the frontmost tubes and at th-e other side engage upon lugs 30 on the flue sheet 'I below the lowermost re tube or flue therein.

In the outer side sheets 9 9, in line with the inlet end extremities 22 of the tubes are wash-out plugs 3| and in the top sheet ID of the boiler shell, in line with the outlet ends 20 of the tubes,

i are wash-out plugs 32.

In the operation of the boiler, of which the rebox forms a part, the tubes absorb heat units -from the products of combustion. Due to the thermic heads thus produced, water and steam are discharged through the outlet ends into the boiler water space above the crown sheet, and water is drawn into the tubes from the side water legs I4, at longitudinally spaced points therein. Thus a continuous circulatory action is established, the inuence of which is exerted in all directions in the side water legs so as to produce a turbulence therein which prevents settling out oi the solids in the water at the bottom of the side water legs. Also, due to the gushing or discharge of water from the outlet -end of the tubes,

` a constant flooding of the crown sheet is effected that insures its complete submergence. Thus even though the water level in the boiler falls below normal, it is assured that the same will at all times be covered with water.

Again, due to the increased circulation'of water through the side water legs, the stresses normally imposed on the side sheets of the i'lrebox are equalized and this of course increases the life of said sheets.

The tubes which are preferably made of seamless rnetal, may be readily bent to shape without cracking and may be easily installed in place.

While in describing the invention, I have referred in detail to the form, arrangement and construction of the parts thereof, the same is to be considered only in the illustrative sense so that I do not wish to be limited thereto except as may be specifically set forth in the appended claims.

I claim as my invention:

1. A locomotive rebox embodying therein a crown sheet and side sheets, a set of circulator tubes arranged on each side of the longitudinal median line of the crown sheet, each tube including an inlet end portion opening through an associated side sheet, an outlet end portion opening through the crown sheet and an intermediate portion of reverse curvature connecting said inlet and outlet end portions, the intermediate portions of the tubes in one set substantially abutting the like portions of the tubes in the other set near the longitudinal median line of the rebox, and arch brick supported on the inlet end portions of the tubes in both sets and meeting on said line.

2. A locomotive rebox embodying therein'a crown sheet and side sheets, a set of circulator tubes arranged on each side of the longitudinal median line of the crown sheet, each tube including an inlet end portion opening through an associated side sheet, an outlet end portion opening through the crown sheet and an intermediate portion of reverse curvature connecting said inl-et and outlet end portions, the intermediate portions of the tubes in one se-t being disposed in substantially close relation to the intermediate portions of the tubes in the other set near the longitudinal median line of the firebox, and arch brick supported on said inlet end portions and parts of said intermediate portions of the tubes of both sets and meeting in the longitudinal median line of the rebox to form a closed arch.

3, A locomotive iirebox embodying therein a crown sheet and side sheets, a set of circulator tubes arranged on each side of the longitudinal median line of the crown sheet, each tube including an inlet end portion opening through an associated side sheet, an outlet end portion opening through the crown sheet and an intermediate portion of reverse curvature connecting said inlet and outlet end portions, the intermediate portion of the tubes in one set being disposed in substantially close relation to the intermediate portion oi the tubes in the other set near the longitudinal median line of the rebox, the tubes in each set being successively longer as they approach the front of the rebox and the inlet ends of the tubes in each set opening through the associated side sheet at successively lower points toward the front end of the firebox, and arch brick supported on said inlet end portions and parts of said intermediate portions of the tubes of both sets.

GUST J. CHRISTENSON. 

